The function of an insulating material in construction is far from the last. Despite the improvement in the characteristics of finishing materials, only reliable and durable insulators can save the house from heat loss and the harmful effects of moisture. At the same time, traditional heat insulators are gradually losing their relevance against the background of increasing requirements for the performance of buildings. Their place is taken by a hydro-vapor barrier film, which also contains thermal protection at its core, but does not allow it to become waterlogged. In essence, this is a multifunctional protective barrier with which you can protect the structure from cold and moisture.
What is hydro vapor barrier?
The concept of hydro vapor barrier is complicated by the functions of the material that can bear such a name. In the usual view, this is a membrane that is used to provide protection for a heat insulator. The most important thing is the phenomena and influences from which it protects. Depending on the field of application, it can be steam, moisture, cold, wind, etc. The composition of the hydrovapor barrier film also differs - in this regard, we can distinguishprofiled and flat membranes. The first are made of polyethylene in the form of sheets with round or square protrusions resembling spikes. Flat membranes are produced not only from polyethylene. Polyolefin and even polyvinyl chloride are also used in production. The result is a film whose thickness does not exceed 2 mm. Usually, a flat film less than 1 mm thick is used in roofing and finishing materials, and thicker membranes are used to protect the foundation.
Hydro vapor barrier characteristics
Technical data regarding the properties of hydrovapor barrier differ depending on the specific material. For example, it is worth considering the characteristics that the Izospan waterproofing film has. This is one of the most popular materials on the Russian market in this segment, according to reviews:
- Material: 100% polypropylene.
- Tearing load transverse/longitudinal, N/5 cm: 107/130.
- Vapor permeability, δ: not less than 7.
- UV stability: 3-4 months period.
- Water resistance: water column not less than 1000 mm.
- Temperature range in which material can be used: from -60 to + 80 ºC.
Use of material in roof insulation
Usually, in the design of roofing cakes, hydro vapor barriers act as a direct barrier against moisture, and also provide wind protection. This is just the casewhen high demands are placed on insulators in terms of strength and durability. As a rule, a waterproofing film for a roof is laid on a heater without a ventilation gap. This decision is due to economic feasibility in the form of reducing the cost of installing a crate between a separate heat insulator and a membrane. Windproof films with the effects of vapor and waterproofing can be used as subroofing layers in roof structures with different slopes, since fixation is provided over the rafters above the insulation. The resulting coating acts as an insulating element for the supporting structure, protecting it from the penetration of under-roof condensate, as well as from wind, rain and snow.
Application in stud wall insulation
The installation of the main walls of the house structure also involves the provision of vapor and waterproofing. In this case, the film protects the material from atmospheric moisture, gusts of wind and powders. But there is, as evidenced by the reviews of the masters, another important function that a waterproofing film for roofing and frame walls should have is the ability to remove vapors from a fibrous insulation material.
The film is installed under the outer skin of the house on the outside of the heat insulator. It is desirable to mount it throughout the frame on top of the insulation in a horizontal position. The joints are made with an overlap of 10 cm. The final fixation is performed with a stapler. It is important to consider that when performing further finishing should bea ventilation gap of about 3-4 cm is left. It is necessary to ensure the removal of moisture.
Hydro vapor barrier of floors
The material should be laid between the ceiling finish and its rough surface, as well as on the floor beams over the insulation. In this case, an increased gap of up to 20 cm is also made. To ensure the tightness of the barrier, the waterproofing film for the floor is additionally fastened with a special tape. This material is also supplied by insulator manufacturers and serves as a connecting element.
It is important to note that if the rooms connected by an insulated interfloor overlap have different temperature conditions, then it is necessary to select an insulating material with extended functionality. So, in addition to hydro and vapor barrier, it is necessary to provide for the ability of the barrier to reflect heat flows. For example, a hydro vapor barrier film that is planned to be laid in an attic or attic should have similar qualities.
Hydro vapor barrier of internal walls
When insulating the frame walls from the inside, two tasks are performed: vapor barrier and preventing the spread of unsafe particles of insulation throughout the living quarters. The membranes are fixed on both sides of the insulation on the supporting bases in the form of racks and beams. Also, if possible, a hydro-vapor barrier film can be attached to the surface of the rough finish. Installation is again done with a stapler or galvanized nails. But in this case, the overlap should be at least 15 cm. If further wall decoration is plannedclapboard or plywood, then the insulation can be attached using vertical wooden slats that have undergone antiseptic treatment. Also, a 3-4 cm gap is maintained between the trim and the membrane.
How to choose the right vapor barrier?
In the choice of any insulating material, the importance of the design that is planned to provide this protection increases. That is, to begin with, threats to the place of application are determined, and then a hydrovapor barrier film is purchased. How to choose this material is not an easy question, it should take into account several points. First you need to decide on the origin of the membrane itself. Usually it is polyethylene. It is advisable to choose a perforated film, as it is the most durable. With skillful installation, it can provide a durable and effective barrier to moisture and wind.
If tensile strength is not a fundamental criterion, then a flat hydro-vapor barrier film may also be suitable. The price in this case will be low - a roll can be purchased for 1000-1200 rubles. If a reinforced film with a metal layer is purchased, then you should be prepared to pay 2000-3000 rubles for it. But with its help, you can effectively provide not only functional insulation, but also durable.
Reviews on waterproofing
More recently, the negative factors from which hydrovapor barriers are used, builders and architects soughtexcluded by the choice of certain materials for structures and finishes. But this approach significantly limits technological solutions. The use of insulating membranes, in turn, practically does not entail similar effects for the home. This, in particular, is confirmed by the Tyvek solid waterproofing film, reviews of which note the benefits of its use. Reducing the moisture content in the space between the finish and the rough coat, coupled with maintaining the integrity of the thermal insulator, is only part of the benefits that the insulator has provided.
Conclusion
For all their popularity, membranes for hydro and vapor barriers are still a relatively new invention. Insulation was the first of this group of materials to appear on the market, but its use in rooms with high humidity was ineffective and necessitated another protective layer - this is how a hydrovapor barrier film appeared. How to choose the right membrane and how to install it correctly are the main questions that consumers face. And the manufacturers of these materials are working hard on them, improving both the operational qualities and the laying technique. At this stage, companies can offer highly effective insulators that can not only keep the insulation from moisture, but also provide a durable barrier against precipitation and wind.
